Method of disintegration, dispersion, stabilization, and collection of solid materials



L. M. McBRlDE nE'rHon oF DISINTEGRATION, msPERsIoN, sTABIILIzA'rIoN;

AND coLLEcTIoN oF soun MATERIALS Filed Aug. 12, 1935 EW/5M Mc SQ/01s' BYWmw@ ATTORNEY.

2 Sheds-Sheet 1 July ll, 1939. M. MCBRIDE' 2,165,287 UETHOD 0F.DISINTEGRATION, DISPERSION. *STABILIZATIOK 1 AND COLLECTION OF SOLIDMATERIALS Filed Aug. 12, 1935 2 Sheets-Sheet 2 INVENTOR. EW/s M Mc.5R/DE BY V4.

ATTORNEY.

UNITED STATES DISINTEGRATION, DISPER- METHOD OF PATENT OFFICE SION,STABILIZATION, AND COLLECTION 0F SOLID MATERIALS Lewis M. McBride,Corozal, C. Z.`

Application August 12, 1935, Serial No. 35,720

6 Claims.

(Granted under the act of March 3, 1883, as amended April 30, 1928; 3700. G. '757) The invention described herein may be manufactured and usedby or for the Government for governmental purposes, Without the paymentto me of any royalty thereon.

This invention relates to the disintegration of solid substances, thedispersion thereof after disintegration, a means of stabilizing the fineparticles of disintegrated and dispersed material to prevent recombiningand a means of collecting 10 the disintegrated, dispersed and stabilizedsubstance or substances.

One of the objects of this invention is to provide a method of producinga fine dust-like material that will retain its characteristics Withoutrecombining into larger particles.

Another object is to provide a means of intensifying, increasing orenabling the capacity or ability of ne dust particles to adsorb uponthemselves a nlm of air or other gas.

Another object is to provide a means to facilitate and augment thenatural tendency of line dust particles to acquire a definite electricalcharge. l

Another object is to provide a means of producing a substance consistingof one material as an active component and another material as an inertcomponent, disintegrated simultaneously and intimately associatedtogether, whereby the particles of inert material tend to assist inpreventing the recombining or cohering of the active particles, thewhole consisting of stabilized particles of active material withattached or adsorbed particles of inert material.

Another object is to provide a means of pro- 3 5 ducing a nely dividedsolid material consisting of two or more components of active materialin a stabilized condition, such that the individual particles of onecomponent will not recombine or cohere With other particles of the samecomponent and, also, such that the particles of diiferent componentswill not combine with or adhere to each other.

In all processes of mechanical disintegration, the different particlesinto which the substance is divided have to be torn apart against theforce of cohesion. Disintegration may be accomplished by shearing andtensile stresses grad'- ually applied, as in attrition mills, or by acrushing pressure applied gradually by means of rolls,

or by sudden blows, as in impact machines of come smaller, they form aloose dustthat yields more and more to the applied stress, so that thecrushing effect is increasingly diminished. There comes a point,therefore, in all crushing operations at which the accumulated dbris isfine enough to accommodate itself tothe applied stress without theindividual particles actually being stressed beyond their elastic limit.The rigidity of the mass is then too low for further crushing stressesto produce any eect.

To disintegrate the material further, it is evident that the nestparticles of the dbris which are cushioning the larger remainingparticles against the crushing effect of the process must be removedinorder to allow the disintegration action to continue. To separate thesenest particles from' the coarse and remove them from the crushingprocess and continue the ldisintegration of the remainder is one of theprincipal features of this invention.

The manner in which this is done contributes directly to anotherprincipal feature of the invention by disassociating any aggregates anddispersing the fine particles and isolating them in air or other gaswhereby they are permitted and caused to adsorb upon their surfacesmolecules or films of air or gas; also, by virtue of the process, neparticles of a particular type of material, according to its chemicalnature, acquire an electrical charge of a definite sign, the adsorbedair or gas and/or the effect of the electrical charges produce astabilized particle preventing recombining or the formation ofaggregates of the individual particles. Further, the method used toaccomplish these results is also used to provide a convenient means ofretaining and collecting the processed material for use.

'I'he combination of the successive processes of disintegration,separation, dispersion, stabilization and collection constitute thebasis of this invention and is accomplished by the methods and apparatusas follows.

In the drawings: l

Fig. 1 is a sectionalized side elevation of the disintegration mill.

Fig. 2 is an end view ofFig. `1 with end parts removed.

Fig. 3 is a side elevation of the assembly of the various apparatus ofthe system.

In Fig. 1 is shown the barrel or steel cylinder I, having heads 2, 2provided with bearings 3, 3', rotatably mounted upon a stationary hollowshaft 4 clamped in the supports 5, 5', the .hollow shaft being closed bythe plug 6 and V preferably near the interior ends of the cylinder. Plug6 is held in place by a set screw 6. Enclosed within the barrel I are anumber of steel rollers t arranged to roll freely on the lower interiorcircumference of the cylinder wall. Fig. 2 is an end elevation of Fig. 1with the head 2 and the support 5 removed for clearness.

The barrel I is provided with openings A, B and C spaced 120 degreesapart around the circumference and equidistant longitudinally, themiddle opening B being preferably at about the center of the cylinderand opening A being toward the rear head 2 and leading opening B (by120) when the direction of rotation of the cylinder is as shown by thearrow or counter-clockwise as shown in Fig. 2, while opening C istoward'the front head 2 `and`fcllowing opening B by 120. These openingsmay be closed or opened by means of plugs as shown at B Fig. 1.

In Fig. 3 is shown a side elevation of the assembly of thedisintegrating, dispersing, separating and collecting system in which Iis the mill of Figures 1 and 42, I0 is a motor or other means ofrotatably driving the mill, II is a vacuum exhaust fan driven. by themotor Ilm or other suitable means, the suction side of the fan beingconnected to the open end of the hollow shaft outside of the support 5and arranged to discharge into the centrifugal separator I2 through thepipe I3, the centrifugal separator being provided with a removablymounted collecting receptacle I2a at its lower end and an outlet` at I2bcommunicating with the top of the dust settling and collecting chamberId through the pipe I5, the dust chamber I having 'a removably mountedcollecting receptacle Ilia at its lower end. The walls of the dustchamber It consist of one or more layers of a suitable fabric filterwhich will permit the escape of the discharged and spent air or gas butwhich retains the fine dust particles, -the area of the walls beingproportioned to the volume of air or gas delivered by thel vacuumexhaust fan II, so that the velocity of airl or gas through the illterwill be relatively low.

With reference to Figures 1 and 2, a predetermined charge of materiaLtobe disintegrated is placed within the cylinder I through one of theopenings as at B, and initially the openings A, B and C are closed withplugs, the charge being represented at I6. Upon rotation of the cylinderI upon the stationary hollow shaft 4, the rollers 8, roll over thematerial I6 crushing and breaking it down to a certain extent; some ofthe material I6 is carried around with and over the rollers, which,rising on the side of rotation, are carried up by friction with theinside of the cylinder I of the mill until they are overbalanced abovethe axis of the cylinder and fall back upon the top of following rollersas shown by the line of arrows, giving several impacts upon the top ofsucceeding rollers, further crushing the material I6 by impact.Continuous rotation of the cylinder I produces a continuous falling andimpacting of the rollers 8. However, a point is soon reached where theaccumulated line material acts as a cushion, as hereinbefore explained,and this condition is overcome as follows: First, withthe end fla of thehollow shaft Il open, the vacuum exhauster is started and draws airthrough lla, and the pipe l and,A across through the top `of theinterior of the cylinder and Iout through pipe removing the fine dustcarried into the air by the continuing action of the cylinder androllers.

This, however, removes only a portion of the extremely fine dust and tocomplete the process, the cylinder is stopped and with the vacuumexhauster still operating, one or all of the plugs A', B and C areremoved and the rotation of the cylinder again started. (The opening lamay or may not 'be closed depending upon the extent of vacuum producedby the exhauster.)

The vacuum exhauster now draws air in through the openings A, B and C,preventing any of the material from falling out, and removes the finematerial from under and between the rollers carrying it through the pipe'l allowing only the comparatively coarse uncrushed material to remain,upon which the action of the disintegrating process continuesunobstructed.

The uniform angular spacing of the openings and the manner in which theylead one another successively from rear to front tends to agitata thematerial under and between the entire surface of the rollers and tocarry the i'lnes from the rear to the front and-out of the pipe l. Theconstant and continuous removal of the fine particles permits thedisintegrating action of the mill to reduce the last remaining materialto the nest proportions.

Referring to Fig. 3, the vacuum exhauster I I is preferably amultibladed high speed type, and serves a triple purpose; first, forproducing a partial vacuum through the mill and removing the neparticles as described; second, to break up any aggregates of fineparticles and to agitate and isolate individual particles/in the airstream; and, third,to maintain the particles in the air stream for adefinite period of time by discharging through a considerable length ofpipe I3 into a centrifugal separator I2 specially proportioned withreference to the fine nature of the material handled. Although thisseparator is similar to a standard type of centrifuging collector asused commercially for various purposes it is used in this process as aseparator rather than a collector in that the direction of the stream ofhigh velocity, dust laden air being suddenly diverted causes anyaggregation of ne particles, that may have escaped separation previouslyin the process, to be torn apart and isolated.

The receptacle I2a is arranged for the collection and removal of suchmaterial as gravitates to it, while at I2b is a central opening from theseparator connected to the pipe I5 which carries the dust laden air tothe collector I4, allowing the dust to be filtered out of the air by thewalls of filter fabric I4, the finely divided and stabilized particlesbeing nally collected in the removable receptacle Ida. as an impalpablepowder which will not cake or form aggregates.

In some instances it has been found advantageous to mix an inert agentwith the material to be disintegrated and stabilized. Preferably theAinert agent and the material are mixed prior to disintegration and thenare fed into the mill. The fine particles are thus thoroughly mixed andare carried forward in the gaseous medium. Although the invention is notlimited to this theory, I believe that the inert particles collectaround the surface of each particle of the active materiaL'thuspositively separating the particles of active material. Y

In the preparation of stabilized tear gas, the chloracetophenone 'hasbeen mixed with such stabilizers as fullers earth, chalk, magnesiumoxide (calcined) or zinc oxide. I have found that not over 5% by weightcf these stabilizing mateand diphenylamine chlorarsine may bedisinterials effectively prevents cohesion, coalescence or recombiningof the tear gas when collected in bulk after treatment in accordancewith this invention.

Reference has been made herein to the use of i l through the pipe 1',the interior of the cylinder l and out of the pipe 1 and to the vacuumexhauster Il, the operation of which is continued to agitate andseparate the particles' as hereinbefore explained.

In the event that it is desired to mix an amount I of air with anyparticular kind of gas used, one or more of the plugged openings A, Band C may be opened to the atmosphere and the gas pressure so regulatedthat the vacuum exhauster will maintain a partial vacuum within thebarrel I.

Carbon dioxide or nitrogen may be used as the stabilizing gas. If it isdesired that no air be admitted, the rotating drum may be placed in achamber to which the gas is admitted, whereby openings A, B and C willdraw gas only through the material. However, as above indicated, air maybe drawn through the openings A, B and C and gas through the hollowshaft, the proportions being easily varied by varying the gas pressure.

Although not shown in the drawings, ports d ,may bedrilled in the hollowshaft i under the i specific material, it. has been found especiallyuseful in disintegrating, stabilizing and collecting normally solidmaterials used as disabling and incapacitating agents such aschloracetophenone and `diphenylamine chlorarsine. Chloracetophenone,commonly called teargas, is normally a solid and has heretofore beendispersed by dissolving it in an inert liquid, or by mixing it withpowder and slowly burning the powder, or by an explosive charge.

Diphenylamine chlorarsine is also normally a solidv which will decomposeat a relatively low temperature, so that dispersion by a burningmunition results in loss of the diphenylamine chlorarsine. Some loss bydecomposition also occurs when diphenylamine chlorarsine is dispersed byexplosion due to the high temperature.

Chloracetophenone and diphenylamine chlorarsine disintegrated andstabilized in accordance with this invention may be dispersed directlyas very fine dust, since these materials may be loaded in variousmunitions and containers and will not cake or recombine.

Furthermore, two or more of these or similary materials may bedisintegrated andmixed for use together. For` example, chloracetophenonegrated separately in my mill and then mixed in proper proportions, orthe mixture maybe made prior to disintegration. Such a mixture will notcake and may be stored and dispersed in any suitable manner such as byair pressure or from airplane spray or dusting apparatus. Also by' meansof artillery or mortar shell, bombs, 'grenades and other projectiles,static containers or land mines and other devices all of which may beloaded with a bursting charge only suflicient to rupture the body of theprojectile or other container and disperse its contents.

Although certain specific materials have been mentioned herein which maybe disintegrated, stabilized and collected by this method and apparatus,it is to be understood that there are many other material vused in thevarious industries, sciences and arts, either separately or compounded,Imixed or otherwise embodied in or with other materials, that may beadvantageously prepared as a finely divided and stabilized material bythis method. A few of such instances are appended by way ofillustration, as follows: medicines, foods, fuels, ceramics, cements,cosmetics, paints, lubricants, abrasives, insecticides, disinfectants,paper, pencils, polishes, powder, rubber and other materials.

It is also to be understood that the apparatus of this invention hasbeen described and shown in its simplest form for the purpose ofillustration, however, it is apparent that modifications and refinementsmay be made, without departing from the principles involved, such, forexample, as providing a meansof feeding the material, which isto bedisintegrated, into the revolving cylinder of the mill, and foropening.A

and closing the varous nlets of the apparatus without stopping the mill,thereby providing for continuous operation instead of intermittentoperation as described herein. l

In the following claims the term gaseous medium is intended to includeair or gas or a mixture of air and gas.

While I have shown and described the preferred embodiment of thisinvention, I wish it to be understood that I do notY confine myself tothe precise details herein set forth by way of illustration, as it willbe apparent that many changes and variations may be made therein bythose skilled in the art without departing from the invention norexceeding the scope of the appended claims.

I claim:

1. The method of disintegrating and stabilizing normally solid irritantchemical agents material which normally cakes during storage, whichcomprises disintegrating the material and a mag'- nesium oxide to finedust particles continuously extracting only the finest dust particles,suspending and transporting the extracted dust particles of thematerials in a moving stream of air, and collecting the fine dustparticles vtl'ius stabilized.

2. The method of disintegrating and stabilizing lchloracetophenone toform a fine dust which and diphenylamine chlorarsine in stabilizedpowder form for use as an offensive chemicalagent chloracetophenone anddiphenylamine chlorarsine together to ine dust particles, intimatelymixed, continuously extracting only thefinest dust particles, suspendingthe mixed dust particles in air until they are stabilized, and co1-lecting the mixed ne particles.

4. The method of disintegrating and stabilizing chloracetophenone and/ordiphenylaminechlorarsine into fine dust particles which will not caketogether during storage by the use of a rotary disintegrating impactmill, which comprises disintegrating the chloracetophenone and/ordiphenylaminechlorarsine to ne dust, continuously withdrawing the verynely ground particles from an area spaced a substantial distance abovethe disintegrating area, and away from the turbulence of such areawhereby only the iinest oating Vparticles are withdrawn, keeping saidarenas? particles suspended in a gaseous medium until each particle issurrounded by attached molecules of the gaseous medium, and collectingthe stabilized particles.

5. The invention as dened in. claim .4, the

additional step of withdrawing the nely ground LEwIs MMCBRIDE.

